Power transmission mechanism



Aug. 3, 1954 H. AUGER POWER TRANSMISSION MECHANISM l2 Sheets-Sheet 1 Filed Dec. 27, 1946 Aug. 3, 1 954 POWER TRANSMISSION MECHANISM Filed Dec. 27, 1946 HAUGER' 2;ss5,26o

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H. AUGER POWER TRANSMISSION MECHANISM Aug. 3, 1954 l2 Sheets-Sheet 4 Filed Dec. 27, I946 Aug. 3, 1954 H. AUGER POWER TRANSMISSION MECHANISM 12 Sheet s-Sheet 5 Filed Dec. 27, 1946 SM @K Q Q 7/1 A A? S7 AS S7. MJA 7 A AY S7 /AS S7 A ST A S 27/ A? S? 41 \S S r SQ SSS fix Q S7 A S? H /A S S wk ST A? Sr Z S w Sr AS S7 Y/AA T w S7 AS \S7 2 2 v m QWM Aug. 3, 1954 H. A UGER 2,635,260 POWER TRANSMISSION MECHANISM Filed Dec. 27, 1946 l2 Sheets-Sheet 6 H. AUGER 2,685,260 POWER TRANSMISSION MECHANISM Aug 3, 1954 Filed Dec. 27, 1946 i 12 Sheets-Sheet 7 Aug. 3, 1954 H. AUGER 2,685,260

' POWER TRANSMISSION MECHANIISM Filed Dec. 27, 194e I 12 Sheets-Sheet s Aug. 3, 1954 H. AUGER 2,685,260 POWER TRANSMISSION MECHANISM Filed DEC. 27, 1946 l2 Sheets-Sheet 9 Aug-3,1954 -H. AUGER 2,685,260.

I POWER TRANSMISSION MECHANISM I Filed Dec. 27, 1946 I 12 Sheets- Sheet 1o Aug. 3, 1954 H. AUGER POWER TRANSMISSIONMECHANISM 12 Sheets-Sheet 1'1 F'iled Dec. 27, 1946 w. k an Aug. 3, 1954 H. AUGER 'Pow R TRANSMISSION MECHANISM IZ'Sheets-Shet 12 Filed Dec. 27, 1946 am fiwsw S Q.. ia

. Q x wfi w .Q w m x xx Patented Aug. 3, 1954 UNI TED JS TATES T QF-FICE POWER TRAN'S MIS SION MECHANISM Harold Auger, Maidenhead, England Application-December 27, 1946, SerialNo. 718,737

Claims priority,'-"-application Great Britain January 4,4946

37 Claims. ..1

This invention relates vto power transmission mechanismsand the employment-thereof in movinga load between two spaeedpositions of rest.

A principalobject ofitheinventioniis toenable a constant speed power source .to. be:used'-for this purpose such as a simple electric'motor and simple limit. switches, and .to render. complex out affecting the load;

To provide an improved drivinglmechanism which has the abovecharacteristics and which is adapted to reciprocate any desiredlusefuliload,

such as (for-example, but not \byuwaynof :limitation) the tableof aplaningmachineorlthezplatforms of mechanical storage equipment-formotor vehiclesor other objects;

To improve mechanical storage'equipmentlof thekind inwhich such vehicles or otheri- 'stored objects are circulated :on movable platformsnby successive movements of thelatter along and between ranks of suchplatformsthemovements being carried out smoothly, and the-driveme'chanismv occupying the minimum possible-vertical depth so as to be accommodated within the floor thickness of a modernsteel frame: building-and to afford substantially uninterrupted floor ..'surfaces; and

To provide, in such storage equipment, im-

proved means. for coupling and' uncoupling the platforms to and from-the "driving: mechanism and for blocking the platform against-movement when desired.

A simple driving mechanism embodying the present invention :may comprise a 'wheel or I disc, and a fixed, straight horizontal track-.alongwhic-h the Wheel is rolled back and forth, thelwheelrcarrying a crank pin or coupling which is located adjacent the rolling periphery OfltheuWhS'fiLi and the coupling being connectedto 'ai'reciprocable load by means such. as the usual pitm'an. 9 Thus as the wheel rolls along the-track, starting and finishing with thecoupling-at thetrack-levelg the coupling describes a cycloidal curve in space;-and substantially the horizontal component -'of Y the cycloidal motion r of l the coupling is -imparted to the load. As the wheel rolls along the trackfithe load accelerates from-restuntil itamomentarilyiatless band, and the pitmanextends :until one of the Wheels :cou-pling moves around the outer periphery of this-wheel and describe the firstpart of a cycloi- .andxfinally passes. around tains twice the translational velocity of the wheel, and then decelerates to' rest after travelling a :distance equal to the rolling periphery ofthe :wheel.

Due to the cycloidal motion of the coupling; the initial acceleration and final deceleration of the load are zero or substantially so.

Another embodiment of the present invention may :use an elongated carriage instead of the simple rolling wheel. Such a carriage may comprise a pair-0f substantially coplanar Wheels journaled at spaced points one chassis or frame, and anzendless flexibleband which encircles and-is free to :circulate about the wheels. In this form of the invention, the coupling is fixed to theendbetween the couplingandload as before. The carriage may move-along the same horizontal track',travelling .on the flexible band, much rolls on its Caterpillar treads.

as a military tank "As the carriage moves, starting with the coupling lying at the level of the track'andsbetween the wheel centers; the coupling remains stationary passes over it. Then the dal curve in space; it then moves along the upper run of the flexible band,*between; the two-swheels, the outside periphery of the; second wheel in describing the final halfaofaa .cycloidal curve. After the coupling returns to the track level, it remains stationary eventhough the carriage may continue on for some distance. The carriage may thus overrunivvithout affecting-the position of the load, so longas the overrun does not exceed the distance between centers ofxthe carriage wheels.

-Asthe-earriagemoves;the load accelerates from rest until it attains twice the translational velocity of thecarriage, maintains this speed while thecouplingmoves along the upper'run of the flexiblebandyandthen decelerates to rest, the initial acceleration and finalideceleration being zero or substantially so, and the startingand finishing positions of the load being precisely-determined inspite of any overrun of the carriage within the above limits.

The carriage-may, of course, takea number of forms other than the elongated one just described. It may be circular, forexample, and the flexible band may be circulated about it in a circular path. In whatever form, the=.-chassis itself does not rotate. But-since the motion of the. coupling is the same whether. itiis Jmounted at the rolling periphery of an actuali wheel or acsaeco on a circular band on a circular carriage, and since the coupling also has in part the same motion when mounted on an elongated flexible band on a two-wheel carriage, it is sometimes convenient to call the back and forth motion of the carriage a rolling movement (in the same sense that a military tank rolls on its treads), and to refer to the flexible band as defining the rolling periphery of the mobile member.

Viewed in a broader sense, the driving mechanism of the present invention includes a mobile member (which may be the above wheel or carriage, or its equivalent) having one connection to the load (this connection may be the coupling or its equivalent) and another connection to a relatively fixed anchor (the anchor may be the fixed track or its equivalent, and the second connection may be the rolling connection between the mobile member and the anchor). The mobile member is capable of traveling bodily with respect to both the load and the anchor along a predetermined path which has at least a component paralleling the direction in which the load is displaced. The coupling is arranged to be driven simultaneously along another predetermined path, which is defined upon the mobile member (as by the two wheels of the elongated carriage), and which in part at least lies transverse to the path of the load. A power source, such as an electric motor, either drives the coupling directly and thus causes resultant translational movement of the mobile member, or it drives the mobile member directly and thus causes resultant movement of the coupling in its path. Components of the motions of the coupling and of the mobile member which are transverse to the direction of load displacement are discarded, as by means of the pitman, so that the resultant motion of the load is a composite of selected components of the simultaneous movements of the mobile member in its path and of the coupling in its path upon the mobile member. Since the mechanism modifies the simple motion characteristics of the power source, it may be referred to as a driven modulating mechanism.

At one or both of its end points, the path of the coupling as defined upon the mobile member is substantially parallel with the path of the mobile member. The mechanism is so proportioned and arranged that at one or both end points of the couplings said path, the relative motion be tween the coupling and the mobile member parallel with the load displacement is substantially equal and opposite to the actual travel of the mobile member itself in a direction parallel with the load displacement, so that these two motions momentarily neutralize one another, Hence, at one or both ends of the loads path, and independently of the acceleration or deceleration of the mobile member or of the power source, the resultant motion transmitted to the load is inherently zero or substantially so. So too are the terminal velocity, acceleration and deceleration of the load.

Preferably the mobile member makes positive rolling engagement with the track, primarily to prevent slippage. Thus the track may be in the form of a toothed rack and the flexible band may be a link chain meshing therewith.

Since the driving mechanisms of this invention reciprocate back and forth, terms used herein to describe the movement of the load, of the mobile member, or of the coupling are intended to include both forward and reverse motion in a such directions, unless the context indicates to the contrary.

The same motion characteristics described above can be obtained with invert forms of these mechanisms, in which the track, instead of being relatively fixed, is free to move and is connected directly to the load to cause displacement thereof. The coupling, on the other hand, is then restrained from substantial motion in the direction of the load displacement, and the mobile member thus travels back and forth when the coupling is caused to move in its predetermined path on the mobile member. The direction in which the track and the load move depend upon the direction in which the coupling moves in its path.

Load driving mechanism according to the present invention may include (a) one of the drive modulating mechanisms just described, (b) an intermediate member which may be called a collector, and which is reciprocated by the modulating mechanism between two spaced terminal positions, and (0) load coupler means, operable when the collector is at these positions, for connecting and disconnecting the collector to and from the load. The load coupler means may be reciprocable with the collector, and may be operable at fixed stations that correspond with the terminal positions of the collector, coupler operating means being located at both said stations and being adapted to be actuated simultaneously and in the same sense. The collector thus acts as an intermediate member to permit ready connection and disconnection of the load to and from the drive modulating mechanism. Preferably, while travelling between the fixed operating stations, the load coupler means is positively held either in engagement with the load or disengaged from it.

The load may take the form of platforms or sets of platforms for supporting motor cars or other stored objects in a rank, and the collector may be moved from one of its terminal positions to the other while coupled to a platform, and then return unloaded to the first terminal position to pick up another platform. It is preferable for the length of each platform or set of platforms to be substantially equal to the distance between the load coupling stations, so that the platforms may be end-coupled to one another to form one or more continuous trains or ranks.

Means may also be provided at the load couplin stations for selectively blocking or freezing the platforms when they are disconnected from the collector.

In general, storage equipment comprising plat forms for supporting motor cars or other objects in a rank may, according to the present invention, include a collector which is reciprocable between two spaced positions along the rank, a driving mechanism for thus moving the collector, load coupler means operable for connecting and disconnecting the collector to and from the platforms when the collector occupies either of said spaced positions, and load coupler operating means which may also block the platforms when and while the latter are disconnected from the collector. Such operating means may also be adapted to block the platforms in a manner that leaves the collector free to reciprocate unloaded, or alternatively, to allow the platforms freedom of movement when disconnected from the collector.

The invention and certain of its applications i5 will-now' be "described byway of example -with reference to the accompanying-drawings; whereof:

Figure 1 is aperspective view-of-a simple' form of thedrive modulating mechanism comprising a single rolling wheel;

--Figure la shows the mechanism f Figure 1 arranged to drive the table of a planing machine;

Figure '2-shows .typical displacement, velocity and acceleration curves for the single-wheel-form of the-mechanism shown =in Figure 1;

Figure 3 isaside elevationof a two-wheel-end- -lessband form of the drive-modulating mecha- -n1sm;

Figure-3a shows an invert form of the mechanismsof this invention;

:--Figure 3b a fragmentary view of-the left --hand end of Figure -3 showing a driving motor mounted upon the mechanism;

Figure 3c is a cross-seetional view on the line 3c-3c, Figure'3b;

"Figure 4 shows curves similar to those of-Figure 2, but for the two-wheel form of the mecha- -nism shown in Figure 3;

Figures 5a, 5bare diagrams showing plans of storage or parking floors provided with movable platforms for motor cars or otherobjects, which are arranged in such a way asto have either'two vacant spaces (Figure'Sa) or only a single open space (Figure5b), the platforms of each rank being arranged in spaced pairs, each platform adapted to support two of the four wheels 'ofa car;

Figured is a general perspective view of part of-a parking floor of this kind, broken open to show the driving chain of a drive modulating mechanism arranged beneathv the floor surface for moving one of the two parallel ranks of plat forms, it being understood that the otherrank is similarly driven by another like mechanism;

Figure 7 differs fromFigureG only inshowing the drivemodulating mechanism (see-FigureS) inposition'connected to the driving chain-and certain parts of the floor filled in;

Figure 8 is a similar view to Figure 7, showing 'mounted on the drive modulating mechanism-a collector through which the platforms may be drivably connected to the said mechanism;

Figure 9 isamore extended general view showing the mechanism whereby the platformsare coupled and uncoupled to and from the collector or blocked against movement,

Figure 9a being part of Figure 9 to a larger scale; and

Figure 91) being another part of Figure 9 to an enlarged scale;

Figure 10 is a somewhat diagrammatic crosssection along the line IG-Ifl of Figure 9;

Figure 11 is a somewhat diagrammatic crosssection along the line II-II of Figure 9; whilst Figures 12a and 12b together form a somewhat diagrammatic cross-section "along the line I2w-I2b of Figure 9.

In the mechanismshown in Figure 1, the bed Ihas a flanged top 2 forming a guide for two slides, one 3 of which forms the drive modulating carriage whilst to the other l of which the load, e. g. the reciprocable table 4a of aplaning machine (see Figure 1a), may be connected. 'One of the lower flanges of the bed hason its upper face a toothed rack 5 along which is adapted to roll the gear wheel 5 mounted on the transverse shaft 1 of carriage 3 which'also carries an electric motor '8 provided with an electro-magnetic brakes and with a toothed pinioniIIl-engaging .pendicular to rack 5 both atthe'beginning' at the end of each revolution of the Wheel. It

mobile member itself, 3 and wheel 6,the path of pin circular path is substantially .locity in units of distance wheelfi. 0n the outer face ofawheel 61 is:a::c.ou =pling in the form of crank. pin: II .pivotallyzacou- :pled to-one end of the link orpitman I2,I '.the

other end of which is similarlypivoted' to...pin..l3

:on slide 4. Slide lisa collector,:.as that .term

has been used above, since. it is an intermediate member betweenthe load (e. g.,rthe planertable) on the one hand and the: crank pin II and'pit- :man I2 onntheother. hand, and sincecit serves to collect and transmit to. thelloadlthedesired component of the motion of the crank pin, in this instance the horizontal component thereof. The mounting of this coupling pin I I on the face *of wheel-6 is-made adjustable radially of the wheel in- 'guides -Ie-so as to permit variation-in the throw of the crank-whilst the mounting of '-pin- I3 -on"slide- 4 issimialrly made adjustable in the directionofreciprocation. Limit switches .(not shown), in the electrical power circuitto motor 8, are provided to prevent overrun of the sliding carriage 3 beyond the limits represented by one complete revolution of wheelfi.

'Fig, 1a shows the mechanism of Fig. 1 arranged to drive the'table 4a of a common form of planing machine, slide 4 of Fig. 1 taking'the from the positionshown in Figure 1, where the center ofpin II lies at the rolling periphery of the wheel and the pin starts from a position-di- .rectly under the center of-thewheel and adjacent .the rack 5,-the-pin-will trace-a cycloidal curve in spaceand, after a complete revolution of the wheel, will again finditself directly'under the center of the wheel and adjacent the rack, after having travelled horizontally a distance equal to the rolling peripheryof the wheel. It will be observed that a radius vector drawn from the center of wheel Ii to the center of pin II 'rotates with the wheel as the latterrolls, and that this vector is directed downward and lies perand will also be observed that with respect to the which comprises carriage I I is a circle-and that at its end points, i. e., at thebeginning and at the end of each revolution of the wheel; this parallel with the path of the mobile member,-i. e., parallel with ;the rack 5.

'The' horizontal components or projections of the characteristics of the cycloidal motionof the pm I are shown in Figure 2 for the condition of uniform rotation of wheel 5. In Figure 2 the horizontal abscissae represent units of time-since the rotation of the wheel-6 is assumed to beconstant; they also represent 0, which is the angular rotation of the wheel between 0 and 360 (taking 0 .to be the positionshown in Figure 1, where the-radiusxvector from the center of the wheel to the center of pin II is directed vertically downward). The angle!) iS at the same time a measure of the translational displacement of the wheel along the rack 5. The vertical ordinates represent displacement in units of distance, ve-

per unit of time; and acceleration in units of distance per unit of time per unit of time, for the respective curves. 'Broken line I5 represents the horizontal componentof the displacement of pin- I i, viz.; vt-r sin' 0,

where '0 is the uniform tangential velocity of pin ll about shaft 1', t is time, and r is the crank radius at which pin H is set, the curve being drawn for the condition where r is the radius of wheel 6, i. e., where pin H is at the rolling periphery of the wheel. Full-line curve l6 represents the horizontal component of the velocity of pin ll, viz., c(1cos and chain dotted curve 11 represents the horizontal component of the acceleration of pin l I, viz.,

sin 6 1' both of the latter formulae also being for the condition where r is the radius of the wheel.

It will be observed that under these conditions the rotational velocity of pin l at all times equals the translational speed of wheel 6, and that the horizontal velocity of the pin at the beginning and the end of each revolution of the wheel is equal to and directiy opposes the translational speed of the wheel. Thus, entirely apart from any acceleration or deceleration of wheel 8 itself, the resultant horizontal velocity of pin H and of its connected load is zero at both the start and finish of each revolution of the wheel, 1. e., at both ends of the stroke of the drive modulating mechanism of Figure 1. This circumstance will also be observed from Figure 2, in which the horizontal velocity curve I6 of pin 1 I, which curve is a cosine function of 6, starts and finishes at zero. Likewise evident from Figure 2 is the fact that the sine-function curve I? of the pins horizontal acceleration also starts and finishes at zero. Thus in addition to zero terminal velocity, the pin and its connected load also enjoy zero terminal acceleration and deceleration, whereby neither the motor 8 nor any other part of the mechanism is subjected to high starting or braking loads.

Slide 4 and the load to which it is connected partake very closely of the horizontal components of the motion of pin l l which have been described above and are shown in Figure 2, but the motion of the slide and the load diiier somewhat from that of the pin, in a wellknown manner, because of the finite length of the link or pitman l2, as referred to in more detail below. This circumstance, however, does not affect the zero terminal velocity and acceleration characteristics above described.

It should be observed that in the mechanism of Figure 1 it is only when pin H is adjusted so that its center is at the rolling periphery of wheel 6 that the pin traces a true cycloidal curve in space. If the center of the pin is otherwise located, the curve of the pin departs from a true cycloid, and becomes a trochoid. Under such conditions the zero terminal horizontal velocity and acceleration characteristics that are inherent when the pin moves in a cycloid are less completely realized, but substantially negligible terminal horizontal velocity and acceleration are still afforded if the amount by which the center of the pin departs from the rolling periphery of the wheel is small.

Certain disadvantages are inherent in the simple form of drive moduating mechanism shown in Figure 1. For example, maximum velocity of displacement of the load is achieved only momentarily, part way through its travel; the depth of the mechanism, as represented by the diameter of wheel 6, is large in proportion to the displacement of the load which it can effect; and the load is subject to further and undesired displacement if the wheel overruns to any degree at the end of a revolution.

In the mechanism shown in Figure 3 wherein these disadvantages are overcome, the mobile member consists of a two-wheel carriage, the frame of which, denoted by Hi and somewhat schematically shown, carries on axles l9 and 28 at its ends the rotatable sprocket wheels 2! and 22 which are thereby spaced apart in the same plane. Around these sprockets and coplanar therewith extends an endless roller chain 23, the pins 24 of the rollers being laterally extended so that when they come into the lower run of the chain, their ends are able to engage the slots of rack '25 on the base plate 26. A so-called collector 21 for coupling with the load, and having rollers 28 for running along longitudinal guide rails (not shown in Figure 3), is connected through a pivot 29 with one end of a link or pitman 33 whose other end is pivoted on a coupling in the form of pin 3| projecting laterally from a part of the chain. As shown, pin 3i is at the rolling periphery of the carriage, which is defined by the chain 23. Rack 25, link 30 and pin 3! can of course be duplicated on the opposite side of the mobile carriage. The latter may be provided with a portable prime mover to turn the sprocket wheels 2i and 22 as in the Figure 1 arrangement. Such is illustrated in Figures 3b and 30 wherein a shelf 8a is secured to frame I8 by brackets 81). Motor 8 mounted on shelf 8a drives pinion [0 which is meshed with gear 3 secured to sprocket '2l. However in the form illustrated in Figure 3, the carriage is adapted to derive its power from an exterior source by suitably coupling its central shaft 32 to a longitudinally movable chain or other driving means.

Figure 3 shows the modulator carriage at one limit of its effective travel, i. e. with the collector 21 at one terminal position, the other limit being attained when pin 3| reaches a corresponding position beneath the axle 28 of the other sprocket after having passed around the outwardly directed periphery of both sprockets and over the intervening top of the carriage l8. Carriage I8, however, may overrun to the left of the position shown in Figure 3, by as much as the distance between axles l9 and 20, without this having any effect on the collector 21. If, on the contrary, carriage I8 is driven along rack 25 to the right of the position shown, pin 3! will be caused first to ride up sprocket 2! to a position above axle l9 whilst it traces out the first half of a cycloidal curve, then to travel in a straight line along with the top run of the chain at a velocity double that of the carriage and finally, as it rides down sprocket 22 to a position directly beneath axle 29, to trace out the second half of the cycloidal curve. At the right-hand end of its normal travel the carriage may again overrun by as much as the distance between axles l9 and 26, without causing any movement of pin 3| or collector 27.

If, as may happen in the practical construction of the mechanism of Figure 3, the center of pin 3| is not located precisely on the rolling circle of first one and then the other of sprockets 2i and 22, it will be understood that the end portions of the curve traced by the pin will not be opposite halves of a true cycloid, but will be portions of a closely related trochoid, as already explained in connection with the single-wheel mechanism of Figure 1. The complete curve of the loci of pin 3|, consisting of a flat top and 9.". substantially cycloidal end portions, mayfconveniently be called an T extended cycloid curve.

As in the-case -of thesingle-wheel Zversion of this invention, it will'be observedthat a radius vector drawn :from the center of each of sprockets 2| and 22 to the center of pin 3| rotates as the mobile carriage travels-along :rack 25, and that such" radius vector from the center of sprocket 2| is directed downward and lies perpendi'cular to the "rack-at one end of thenormal travel of the carriage, while such radius vector fro'mth'e center 'of sprocket 22 is similarly directed and is similarly perpendicular to the rack'at the other end of the carriages normal travel; It will also be observed that the curvedportions of the path of pin 3| with respect to the mobile member itself, i. e.,- those portions which are traced as the pin skirts the outer peripheries of the sprockets, are substantially opposite arcs :of a circle and that at the end pointsof the path of pin 3| with respect to the carriage, i. e., atthe points at which the pin begins to move in space and at which it is brought to rest in-space, the pins'circular path is substantially parallel with the path of the carriage, i.*e.-; parallel with rack 25.

Assuming the-carriage to be moved at constant velocity and the "pin 3| to lie successively on the rolling circles of sprockets 2| and 22, the characteristicsof'the horizontal components or projections of the motion of the pin are shown in Figure 4,'in which the horizontal abscissa represents both horizontal carriage displacement and units of "time, whilst the vertical ordinate has the-"same multiple significance as inFigure 2. s

The .curves 32a (broken line) for displacement, 33 (full line) for velocity and 34 (chain-dotted) foracceleration of the pin 3| are basedon exactly the samefo'rmulae as those governing Figure 2, except that, in the formulae for the -two-wheel carriage,i0 denotes the angulariposition of pin 3| on first one 'andthenon the other sprocket.

instead of the rotation of the single wheel throughout as in the case of the Figure 1 mechanism, and except that each of the curves of Figure 4 has a central straight portion that corresponds with the displacement of pin 3| in a straight line between the sprockets 2| and .22, such :displacement occurring at auniform velocity which is the. maximum speed attained by the pin. The maximum velocity of displacement can be maintained uniform over any desired distance represented by the straight portions of these curves and depending onthe spacingapart of the sprockets 2|. and'22. Moreover, this is done withismallTdiameter sprockets so that the possible horizontal travel of thecarriage is large in relation to the depth of the mechanism.

Itwillbe observed that underthese conditions the linear velocity of pin 3| with respect to the mobile carriage at all times equals the translational speed of the carriage, and that the horizontal velocity. of the pin at thebeginning and end of the normal travel-of the carriage is equal to and .directlyopposes the translational speed of the carriage, so that as in the case of the sin gle-wheel mechanism of Figure 1, and entirely apart from-any accelerationor deceleration of the two-wheel carriage itself, the resultant horizontal velocity of-pin 3| and of its collector 21 is zero at both" the start and finish of each traverse of the collector. This circumstance will also be observed from Figure-4, in whichi'thehorizontallvelocit'y curve 33 'ofS-the .pin 3l, theend portions ofwhich follow-a cosine function of 0, starts and finishes at zero. Likewise evident from Figure 4 is the fact that the pins horizontal acceleration curve 34, which in its end portions follows a sine function of 0, also starts and. finishesat zero. Thus in addition to zero terminal velocity, pin 3| and its collector 21 enjoy zero terminal-acceleration and deceleration, so that the mechanism does not suffer high starting or braking loads.

As in the case of slide 4 of Figure l, collector 27 of Figure 3 partakes very closely of the horizontal components or projections of the motion of coupling pin 3| which have been described above and are shown in Figure 4, but the motion of the collector differs somewhat from that of the pin, in a well-known manner, because of the finite length of the link or pitman 3E3,'as further dis-" cussed in the next paragraph.

The use of the pivotal links betweenthe drive modulating mechanism and the load in thearrangeinents of both Figures-1 and 3 and the changing inclination of the links, with consequent slight alteration in the spacing of the pivot centres in the direction of travel, leads to corresponding well-known discrepancies between the velocity and other motion characteristics of the pivot pins H and 3| calculated on the basis of the stated formulae, and the motion'characteristics of the respective loads, but the diifer ences are so slight that they can be ignored in practice. These difierences, however; do not af-' feet the transmission to the load or to the collector of the zero terminal velocity and acceleration characteristics of the pins II and 3|. Furthermore, these differences can be eliminated by substituting for the pivoted connecting links l2 and 38 a slotted plate connected to the load, the slot extending transversely to the path of the mobile member and the coupling II or 3| riding in the slot.

If different acceleration characteristics are desired at the ends of the loads travel in the mechanism of Figure 3, the two sprockets 2| and 22 may be of different diameters, in which case the path of pin 3|, consisting of end portions each of which is a portion of a difierent cycloidal curve, and a central portion connecting the end portions, may be called a differential extended cycloid.

In both Figures 1 and 3, it will be observed that the mobile member, i. e., the wheel 6 or the carriage I8, is connected both to the load and to a fixed anchor, the connection to the load in Figure 1 being coupling II which exerts its effect on the load through pitman i2 and slide or collector 1-, and in Figure 3 being coupling 3| which exerts its effect through pitman 3t and collector 21, and the connection to the fixed anchor being the rolling engagement of the mobile member with the fixed track 5 (Figure 7) or 25 (Figure .3), the track being the anchor.

The same motion characteristics of the devices of Figs. 1 and 3 can be obtained by invert-forms of such mechanisms, in which the track is-con-' nected to the load itself and is free to reciprocate, and in which the coupling is restrained against substantial movement in the direction of load displacement. Fig. 3a shows such an invert mechanism, specifically an inversion of the Fig. 1 device.-

In Fig. 3c the same reference characters used in Fig. 1 identify corresponding elements. Bed is no longer fixed as in Fig. 1, but is slidably mounted in fixed pedestals A, B. As before,

flange 2 forms a guide for slide 3 which consti tutes a carriage on-which are mounted gear wheel 6, shaft I, electric motor 8, brake 9 and pinion ill, the latter engaging wheel 8. Toothed rack is fixed to one of the upper flanges of bed I, and meshes with wheel 8. Crank pin or coupling (1 is fixed at the rolling circle of wheel 6, and pitman 12 is pivoted to coupling 1 l and to fixed pivot IS on pedestal A. Coupling l l is thus restrained from any substantial motion lengthwise of bed I, but is free to move transversely (i. e., up and down) as wheel 6 rotates. Carriage 3 and wheel 6 will therefore reciprocate horizontally as the wheel is rotated by motor 3, and bed I and track 5 will also reciprocate horizontally in its pedestal slides, the motion of the reciprocating bed having the same displacement, velocity and acceleration characteristics as slide or collector 4 of the Fig. 1 mechanism. Limit switches (not shown) in circuit with motor 8 confine carriage 3 to a path which is the length of the rolling periphery of wheel 6.

Any desired load, such as the planar table 4a of Fig. 1c, may be connected to reciprocating bed I, and if connected directly thereto will have imparted to it substantially zero acceleration and deceleration.

While Fig. 3a discloses specifically an inversion of the Fig. l mechanism, it will be obvious that the two-wheel carriage modulator mechanism of Fig. 3 can be similarly inverted, by making rack reciprocable on its base plate 26, connecting collector 21 directly to rack 25, and moving pivot 29 from collector 21 to a postion where it is fixed with respect to base plate 26.

As already indicated, the drive modulating mechanism of the present invention, and in particular that of Figure 3, can be employed to advantage in equipment for storing motor cars or other large objects which are carried on platforms (or sets of platforms). These may be arranged in two parallel ranks disposed one above the other or side by side, the cars or the like being circulated by transferring a platform or set of platforms from the end of one rank into a vacant space at the adjacent end of the other rank, advancing the platforms or sets of the first rank one space, so as to leave a vacant space at the opposite end of that rank, transferring into this space a platform or set from the adjacent end of the second rank and so on. In. Figure 5 two possible arrangements are illustrated diagrammatically of thus circulating pairs of platforms a and b in two side by side ranks 36, 3'! of such pairs, Figure 5a showing one in which there are two vacant spaces permitting simultaneous opposite movements in the ranks followed by simultaneous transfer at the opposite ends, i. e. two movements per cycle, whilst according to Figure 5b for use where economy of space is the primary consideration, there is only one vacant space, in which circumstances circulation requires four successive operations for each advance. It will be appreciated that the time of circulation can be halved by using the Figure 5a arrangement as compared with that of Figure 5b.

It is desirable to provide an individual driving mechanism for each rank 36 and 37, operated from a master control which also governs the end traversing mechanism. It is also desirable that this control should extend to suitable mechanism for coupling and uncoupling the driving mechanisms of the ranks to and from the platforms thereof and for blocking the platforms in a rank to prevent creeping thereof when they are required to be stationary. Thus in the Figure 5a lay-out, the platforms of the ranks need to be simultaneously coupled to their respective driving mechanisms and simultaneously uncoupled therefrom and blocked whilst the end traverses are taking place. On the other hand, in the layout of Figure 5b, the platforms of one rank require to be coupled to the driving mechanism thereof whilst those of the other rank are blocked. The present invention is not concerned either with the master control system or with the mechanism for end traversing.

In the parking or storage equipment next to be described and as shown in Figures 6 to 12, the pairs 35a and b of platforms in each main rank 3% and 31 are themselves arranged in subordinate ranks 36a and b and 31a. and b in each of which the individual platforms are respectively coupled togther at the ends. These subordinate ranks are always moved synchronously in the respective main ranks, each of the latter being adapted to be moved by its own drive modulating mechanism, which may be arranged near the middle of the rank between its component subordinate ranks, to and from the platforms of which said mechanism is adapted to be coupled and uncoupled simultaneously, all the platforms of the rank being movable together with one platform in each subordinate rank is driven, by reason of the end couplings between the platforms.

In a pit 38 between the middle part of the runways of the platforms in subordinate ranks 31a and b is arranged (as shown in Figure 6) the drive modulating mechanism for operating the near side rank 31. The longitudinal guide rails 39, formed of inwardly facing channel members arranged to carry the platforms of subordinate rank 31a, are shown in full in Figure 6, but only the foundation girder 40 for the inner guide rail of subordinate rank 311) appears. The endless driving chain 4| for the drive modulating mechanism is itself driven from sprockets 42 one of which is rotatable by shaft 43 from a simple electric motor (not shown). The upper run of this chain is provided with a special link A l by which it makes connection with shaft 32 of the carriage. The chain extends suihciently far to permit of link 44 being reciprocated over a distance covering the required longitudinal travel of the carriage. At its far end the chain passes around an adjustably mounted sprocket 45.

In Figure 7, the carriage l8, which in all essentials resembles that shown in Figure 3, is shown in position with its central shaft 32 coupled with link 44 which in this drawing is of course hidden by the carriage. In addition to the engagement between pins 24 and the slots in the top edges of the rack angle irons 25 on mounting plate 46, stops 4! are provided at either end of the path of pin 3| so as to determine the limiting positions of the latter with precision, for the reasons which will hereinafter appear.

In Figure 8, the collector 21 is shown in position over the carriage l8 and with one of its upper pair of rollers 28 in engagement with one of the channel rails 49 which are substantially similar to those 39 for the platforms. The lower pair of rollers 28 on collector 2'! engage other channel rails 4911 similar to and located just below rails 49. Only the far side rail 49 appears in the drawing (Fig. 8), the near one and its supports being removed for clarity of illustration. Both sets of rails 49 extend just sufficiently far to cover the distance over which collector 21 has to reciprocate backwards and forwards, which distance is in fact the length of one of the platforms, so that when the collector is at one end of its path it can be appropriately coupled to a platform and then be shifted with the latter to the other end of its path, where it'can, on being detached, be-

movedback free to'its first position where the next platform will be ready to be similarly couures 9,911 and 9b and will next be described. The" pit 38 containing the drive-modulating mechanism and with the collector 21 reciprocating over it,is shown-for the-near side rank 37 only with the collector at its near limiting position. All the platforms 35a and 1) throughout the equipment are similar, each being preferably formed as shown with a grid-like treadface 59 having overhanging side edge border flanges 5i and pairs of rollers 52 atintervals'along its length for running within the rails 39, the top flanges of which are overlaid by the flanges 5| of the platforms. Adjacent ends of the platforms are closely intercoupled at 53 by meanswhich permits of the required. lateral separation for traversing from rank to rank, but which it is not necessary to de-. scribe in detail in connection with the present invention, they being such as, for example, the platform coupling means which are disclosed in my copending application Serial No. 764,77 9, filed July 30, 1947. Figure is a section of rank 31 showing the normal disposition of the platforms with respect to the rails. However, over a distance extending away from one end of pit 38 and from the corresponding limiting position of the collector, such distance being equal to about the length of one platform, the track is modified to the section shown in Figure 11. Over this section, there is accommodated between the adjacent subordinate ranks are and b, a pair of rods 54 one alongside each subordinate rank. At one end, each of these rods'is secured to the collector 21, as by pivoting the end of the rod on the shaft which carries the adjacent wheel 28 (as shown in Figure 9b) so that the rods share in the reciprocation of the collector. At its other end, each rod carries a block 55'on which is pivoted a trigger link 55, capable of lateral-outward swinging from the line of the rod and carrying at its outward extremity a downwardly directed pin or lug 51.- Over the said modified length of track, the inner rails for the platform rollersin each rank (for which purpose the channel rails 39 serve elsewhere as already described) are formed as simple angle members 58 in place of the channels. Alongside these are similar but oppositely directed angle rails 59 on which the rods 54 are adapted to ride. Enclosure of the rods is completed by the inverted angle sections 50, the top flanges of which extend over beneath theadjacent border flanges 59 of the platforms. Under these top flanges and over the top edges of rails 58 and 55 extends a space deep enough to enable the trigger links 56 to be slid through it as hereinafter described. Enlarged parts GI (see especially Fig. 9a) on the rods M form guides engaging the adjacent faces of rails 59 and sections 69 whereby the rods are held against lateral displacement. Holding-down bolts for rails 53 and 59 are provided as at 62 whilst the area between the-border flanges 51 of the platforms occupied by the pit 38, the collector 21 and the parts associated with rods-EeM-is covered in by'plating-(i-i which is substantially on a level with the plat-- able to travel along the respective rails 58'iinr which circumstances, the links 56 being swung:

' i. e. a platform length apart.

form'ztreadszsczthat thetwhole surfacelis .uninrs terrupted.

from the adjacent side of:

ly to accept a lug 57 between'them and thus. to permit the platforms to be driven in either direction. When in engagement with these jaws, lugs 51 are inline with the platform rollers and are outwardly as shown in'Figures 9 and 9a, they'ex tend across the adjacent top edges of rails 58and 59 along which they are able to slide beneath the. top'fianges of sections- E30. On the other hand,"

when lugs 51 are moved towards one another out of engagement with jaws so that the links 5&3

are substantially in line with rods 54,'the lugs'are able to travel along the rails 59.

Coupling and uncoupling to and from the platforms as just described, is possible only'at two stations, viz. those which-lugs 51 occupywhen collector 27 is at either end 'of its traverse,

rails 58' and 59'terminate and the ordinary type rails 39 on the same sides of the platforms commence,. there being, however, a gap left at each such junction through which lugs 57 are able to pass into andoutof'engagement withjaws 94. For moving lugs 57 in the required manner, a cross-traversing coupling-operating mechanism is provided at each station. Extending across the space between the two subordinate ranks 37a and his a guide 56 on which two blocks 67 are slidably mounted. Each of the blocks is provided with an upstanding boss esbapable of being moved into one of the gaps 65 (the position" shown in Figures 9, 9a and 12a) and, in moving up to do this, of pushing lug 5Tbefore 'it through the gap into engagement with the jaw 64'. Each block BIis also formed with a second upstanding boss 69 spaced away from the first and adapted, when the block is moved'in the op-' posite direction, to disengage the lug 5'l'from the jaw and bring it back through the gap into alignmentwith its associated rod 54 (the position shown in Figure 12b). The bosses 59 are then in aposition also to block the rollers "52 of the platforms and so to prevent the latter from creeping. The bosses wand '89 are spaced apart sufficiently to permit of an intermediate position of the blocks in which lugs 57' are not coupled with the platforms by bosses 58, nor are the platform rollers blocked by bosses 69, this position not being assumed in normal working, but being of use in servicing and adjusting the mechanism when free through travel of the platforms may be desired.

The blocks 97' are movable together and apart in'synchronism by means of links iii and 'H arranged on either side thereof and coupled thereto'respectively at E2 and 3 (Figure 9a).

These links are moved in opposite directions througha double bell-crank 7d adapted to be turned by reciprocation of the operating rod 15 which is movable longitudinally of the platform ranks, as by means disclosed in mycopending application Serial No. 764,779, filed-July 30-, 1947."

At these places,-

Rod is' suitably supported at in tervals along its length by brackets 16 where connecting pins ll of its adjacent sections may be slidably anchored in slots in the brackets, and is extended to operate the blocks of the cross-traversing coupling-operating mechanisms at both the aforementioned stations in synchronism and in a similar manner, i. e. so that when the blocks at one such station have engaged lugs 5! with the platforms, the corresponding blocks at the other station will be ready to receive the lugs in that condition and then to disengage them from the platforms. Similar considerations apply when the lugs 5'! are moved unloaded along rails 59.

In addition to operating the cross-traversing coupling-operating mechanisms of the near rank 31, it is a matter of convenience that the rod 15 and bell-cranks M should also be used to operate, through extension links l8 and 19, the

identically similar mechanisms of the far rank 36 since all preferably work in synchronism. However, for operation according to the layout of Figure 5?), it is desirable for the platforms of rank 35 to be blocked whilst those of rank 31 are coupled to the collector of that rank. Accordingly, as shown in Figures 9a and 12a and b, the blocks 61 in each of the cross-traversing coupling-operating mechanisms are connected by the extension links 18 and 19 in such a way that the two outside blocks are connected I to one of the links and the two inside blocks to the other link, so that the blocks of the respec tive pairs move simultaneously in an opposite sense in the two ranks. However, for operation according to the lay-out of Figure 5c, the connection is made such that the right-hand block in each of the ranks is connected to one of the links and the left-hand block in each rank to the other link, so that the blocks of the respective pairs move in the same sense in the two ranks.

It will be seen how, by operation in appropriately timed sequence of the constant speed motors of the drive modulating mechanisms of the respective ranks backwardly or forwardly and of another motor acting to reciprocate rod 75, the whole equipment can be actuated in accordance with any desired system of circulation by means of a suitable master control of the motors.

I claim:

1. Driv modulating mechanism for displacing a load from one position of rest to another such position, comprising a mobile member, a flexible band movable about the mobile member, a con nection from the flexible band to the load and also a connection from the flexible band to a fixed anchor, said connections permitting travel of the mobile member relatively both to the load and to the anchor, and a coupling pin on the flexible band constituting one of such connections and being constrained by movement of the flexible band to follow a circuit on the mobile member an end of said circuit being substantially adjacent the other such connection, and said mechanism being so constructed and ar ranged that said coupling pin is caused to traverse said circuit with the flexible band, with corresponding travel of the mobile member under restraint of the other such connection, whereby the load becomes displaced with respect to the anchor at low terminal acceleration and deceleration.

2. Drive modulating mechanism according to claim 1, wherein the coupling pin is adapted to be connected to the load, said anchor includes a track, and said mobile member is adapted to be moved along said track.

3. Drive modulating mechanism according to claim 1, wherein the path of motion of the flexible band on the mobile member is semi-circular at its ends with a tangential reach therebetween.

e. Drive modulating mechanism according to claim 1, in which said anchor includes a straight track engaged by said mobile member.

5. Drive modulating mechanism according to claim 1, in which said anchor includes a rack with which said flexible band is adapted to make positive engagement.

6. Drive modulating mechanism according to claim 1, wherein the coupling pin is adapted to be connected to the load and the mobile memher is adapted always to move in the direction in which the load is displaced.

7. Drive modulating mechanism according to claim 1, wherein the mobile member takes the form of a chassis with said flexible band passing around it to provide a carriage adapted to be moved along a relatively fixed track, the engagement of the carriage with the track constituting said other connection, and said coupling pin being adapted to be connected to the load.

8. Drive modulating mechanism for displacing a load from one position, of rest to another such position comprising a mobile member, a flexible band movable about the mobile member, means included in said mobile member to hold the flexible band elongated in the direction of movement of said member, a connection from the flexible band to the load and also a connection from the flexible band to a fixed anchor, said connections permitting travel of the mobile member relatively both to the load and to the anchor. and a coupl ng pin on the flexible band constituting one of such connections and being constrained by movement of the flexible band to follow a circuit on the mobile member, an end of said circuit being substantially adjacent the other such connection, and said mechanism being so constructed and arranged that said coupling pin is caused to traverse said circuit with the flexible band, with corresponding travel of the mobile member under restraint of the other such connection, whereby the load becomes displaced with respect to the anchor at low terminal acceleration and deceleration.

9. Drive modulating mechanism according to claim 8, wherein the flexible band passes around two wheels lying in the same plane and having their axes spaced apart in the direction of movement of the mobile member.

10. Drive modulating mechanism according to claim 8, wherein the mobile member is adapted to overrun outside the limits of movement of the load without eflect on the latter.

11. Drive modulating mechanism according to claim 1, including a pivotal linkage between said coupling pin and the load, whereby said pin transmits to the load the component of said pins movement in the direction of travel of the load.

12. Drive modulating mechanism according to claim 1, in combination with a constant speed power source drivably connected to said mobile member.

13. Drive modulating mechanism according to claim 1, including a power source and a chain adapted to be driven by said power source in the direction of movement of said mobile member, said chain being drivably connected to said mobile member. 

